Evolution of Gold Buyers; Moving to Pin-Dips for Instant Assay

One of the most common applications of Quickshot XRF analyzers is the accurate quantification of gold and other precious metals.  Having provided solutions to this industry since our first days, we have seen the increased number of gold buyers and the evolution of many.  That evolution will typically develop from using simple karat identification tests (acid tests, etc) when purchasing scrap to utilizing the benefits that x-ray fluorescence technology offers in speed, accuracy and reliability.  The next phase of evolution is when a buyer that began with a focus on just gold content realizes the need for high accuracy on all precious metals – something that XRF can provide.  Whether the interest is just gold or additional precious metals, many buyers will begin melting goods into bars before sending to the refiner and some have actually evolved into refiners.

Gold Bars Tested by XRFWhen clients reach the point of melting down scrap, they will sometimes request consultation on the best methods of precious metal assay.  The experiences staff of Quickshot XRF can assist with a discussion on various approaches to maximize the accuracy of x-ray fluorescence.  One of these methods involves creating pin-dip samples for instant assay; which is a practice used by precious metal refiners as well as gold buyers that melt down scrap.

Instant assay of precious metals and karat alloys uses the XRF technique that requires the samples be very homogenous (uniform throughout) in order to achieve the highest accuracy.  Homogenous is an absolute requirement.  If molten metals are allowed to cool down slowly they usually segregate, or separate, into non-homogenous materials – the outer surface often being richer in gold if it is a karat or scrap.  This affects the accuracy significantly since all XRF analyzers measure only 10-25um into the surface of a sample.  Molten liquid metal is very homogenous if stirred and mixed.  When the molten metal is quickly quenched, or cooled, the uniform distribution of the elements in the liquid metal state is “captured” better and retained in the resulting solid form.  Use of hollow vacuum-evacuated glass tubes, called “pin dip tubes”, facilitates taking proper samples for the instant assay.

A full overview of pin-dip procedures for instant assay is available -
Contact Quickshot XRF staff to request a copy or discuss xray fluorescence for precious metal assay.

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